To provide a system and a method capable of improving the efficiency of loading and unloading work and preventing loads from being left unloaded.

This loading position allocation system 1 is such that a stacking position L on a truck 2 is allocated to a palletizing body W to be loaded on the truck 2. The system 1 has multistage pallet allocation means 4 and one stage pallet allocation means 5 and a reverse unloading order allocation section 7 in the multistage pallet allocation means 4. The multistage pallet allocation means 4 allocates positions where multistage pallets WA out of palletized body W from the front side of the truck 2. The reverse order unloading order allocation section 7 allocates the multistage pallets WA for each destination together in reverse order of the destinations for unloading from the front side of the truck 2. The one stage pallet allocation means 5 compares the number of the remaining pallet placing positions L with the quantity of one stage pallets WB and produces information for stacking one stage pallets WB on another one stage pallets WB according to the comparison result.